Fan assembly



Dec. 9, 1952v o. c. PALMER ET AL FAN ASSEMBLY 2 SHEETS- SHEET l Filed Aug. 7, 1950 DeC- 9 3952 O. C. PALMER ET AL 2,620,970

FAN ASSEMBLY Filed Aug. 7, 1950 2 SHEETS-SHEET 2 I N VEN TORS OSCZQ' C. p MEQ Patented Dec. 9, 1952 FAN ASSEMBLY Oscar C. Palmer, Phoenix, Ariz., and Edward E. Mix, Los Angeles, Calif., assignors to Palmer Manufacturing Corp., Phoenix, Ariz., a corporation of Arizona Application August '7, 1950, Serial No. 178,030

4 Claims.

This invention relates to improvements in fan assemblies and is directed to a novel form of fan construction which is particularly adaptedl for use with an electric motor.

Among the objects of this invention is to provide a fan assembly which may be carried on the shaft of an electric motor which is designed so that the overalllength of the motor and fan assembly may be a minimum.

f- Another object is to provide a fan assembly having a conoidal nose or dome for stream-lining the center portion of the fan with respect to the flow of air generated by the fan.

A more detailed object is to provide a fan assembly having an external shell provided with a conoidal dome and an internal cup which carries a-centrifugal blower to induce flow of air through and around the motor for cooling.

Another object is to provide a device of this type in which the cup and dome cooperate to define an enclosure, and the device having a hub positioned within this enclosure.

Other and more detailed objects and advantages will .appear hereinafter.

In the drawings:

Figure 1 is a perspective view of an exhaust fan assembly, illustrating a preferred embodiment of our invention.

Figure 2 is a rear elevation partly broken away, taken substantially on the lines 2 2 as shown in Figure 1.

Figure 3 is a sectional side elevation, taken substantially on the lines 3 3 as shown in Figure 2.

Figure 4 is a sectional detail, taken substantially on the lines 4 4 as shown in Figure 1.

Figure 5 is a perspective view of the back side of our improved fan construction.

Figure 6 is a perspective View of the cup prior to its installation on the fan assembly.

Figure 7 is a perspective view of the centrifugal blower prior to installation on the fan assembly.

Referring to the drawings, the fan assembly or rotary air impeller, generally designated I0, is adapted'to be secured to'the extending end of the shaft II of the electric motor I2. The motor is supported from its rearward end by means of a support bracket I3 carried within the frame or housing I4. We prefer to provide a resilient mount for the support bracket I3 and, as shown in the drawings, a pair of brackets I5 may be fixed to the housing I4 and arranged to carry the support bracket I3 on rubber blocks I6.

The rotary air impeller IIJ comprises a shell I'I having a rounded or conoidal dome I8 and a cylindrical wall I9 extending from the dome. A

2 cup element 20 is received Within the shell II and this cup element is provided with a cylindrical portion 2I which fits Within the cylindrical wall I9. The cup 20 is pro-vided with a radial ange 22 having a central aperture 23. A hub 24 extends through this aperture 23 and is centrally bored at 25 to receive the motor shaft II. A set screw 25 on the hub engages a flattened portion 21 on the shaft II t0 secure the rotary air im-V peller ID to the motor shaft II. An access aperture 28 may be provided in the dome I8 to permit a screwdriver to be inserted into engagement with the set screw 26 for clamping .the hub 24 to the shaft II.

Brackets 29 are fixed to the outer surface of the cylindrical Wall I9 by means of rivets 30 which extend through the brackets, cylindrical wall and cylindrical portion 2I on the cup 20. Each of these brackets 29 supports one of the impeller blades 3I, which extend radially from the shell I'I and which are curved and shaped to provide quiet efficient operation. Rivets 32 connect each of the brackets 29 to its respective blade 3I We prefer to insert gasket material 33 between each of the brackets and its blade to insure a tight connection and to prevent rattling of the device in service.

As shown clearly in Figure 3, the electric motor I2 extends into the shell I'I and cup 2D and defines an annulus 34. It is important to maintain the overall length of motor and fan assembly at a minimum in order that the Width of the housing I4 may be kept Within desired limits. Considerable saving in axial length is achieved by positioning the motor in the shell, as shown in the drawings.

A bladedblower element 35 is positioned within the shell II and is xed to the flange 22 of the cup 20 by means of rivets 36. Gasket material 31 may be interposed between the blower 35 and flange 22 to maintain a tight joint. The blower 35 is provided with a central aperture 38 to receive a portion of the hub 24. The end 39 of the hub 24 may be deformed by a rolling action'- to secure both the blower 35 and flange 22 with respect te the hub 24.

The blades 4I) on the blower 35 extend outwardly from the shaft II and. when the shaft II is turned by the motor I2, these blades act to move air centrifugally within the shell I'I to cause a flow in the direction of the arrows identied as 4I. This centrifugal action of the blow- `er 35 reduces the air pressure in the region of the forward end of the motor shaft II so that cooling air is caused to flow through the motor l2 and to pass through the annulus 34 between the motor I2 and the cup 20. It will be observed that the ow of air through the annulus 34 is in a direction contrary to the main ow of air impelled by the blades 3|. In the particular construction illustrated in the drawings, the fan assembly rotates clockwise as viewed in Figure 1 and the air is caused to flow axially of the motor shaft in the direction shown by the arrows 42. It has been found by actual tests that the forward end of the motor I2 adjacent the fan lll runs at a considerably cooler temperature when the blower 35 is employed, as compared to tests made with the same apparatus but `omitting the blower 35.

The fan construction embodying our invention is particularly well suited for economical manufacture on a quantity basis. Each of the various parts, with the exception of the relatively small hub 2li, is preferably formed as a stamping from sheet material. rThus, the blades 3|, brackets 29. shell I'|, cup 2G and blower 35, may each be readily formed as a stamping. A rugged mount is provided for the blade brackets 39 by reason of the mutually reinforcing engagement between the cylindrical portion 2| of the cup and the cylindrical wall |9 of the shell Il. Distortion, fluttering and undesirable deflection of the load, are thus eliminated.

The casing I4 may take any suitableor desirable forrn and may be provided with screens or louvers on its various sides. The support bracket |3 for the motor provides a rugged mounting which prevents sagging of the fan ID. The rubber blocks 8 act in tension to support the bracket I3, together with the motor and fan, and these rubber blocks further act as vibration dampeners so that a minimum of vibration is transmitted to the housing 1|4 when the fan is operating. The rubber blocks each preferably include a pair of metallic end flanges 55 which are vulcanized to the rubber material. Bolt means 45 serves to connect the ilanges 45 .to the brackets I3 and I5.

If desired, a fuse box 41 of conventional design may be mounted in the housing M and inserted in one of the electric leads E8 for the motor. This device acts in a well known manner to interrupt the electric circuit in the event the motor should be overloaded for any reason.

Having fully described our invention, it is to be understood that we do not wish to be limited to the details herein set forth but our invention is of the full scope of the appended claims.

We claim:

1. In a rotary air impeller for use with a motor having a shaft, the combination of: a shell having a rounded dome and a cylindrical Wall, im-

peller blades fixed on said cylindrical Wall, a cup fixed within the shell and having a cylindrical portion received within and contacting said wall, the cup having a radial flange element cooperating with the rounded dome to dei-lne an enclosure, a hub within the enclosure, a bladed centrifugal blower element fixed on the flange within the cup for inducing a ow of air through the motor for cooling, means securing at least one of the elements to the hub, and detachable means for connecting the hub to the motor shaft.

2. In a rotary air impeller for use with a motor having a shaft, the combination of: a shell having a conoidal dome and a cylindrical wall, impeller blades fixed on saidcylindrical wall, a cup fixed within the shell and having a cylindrical portion received within and contacting said wall, the cup having a radial flange element cooperating with the conoidal dome to define an enclosure. a hub within the enclosure, a bladed centrifugal blower element fixed on the flange within the cup for inducing a flow of air through the motor for cooling, means securing both of the elements to the hub, and detachable means for connecting the hub to the motor shaft.

3. In a rotary air impeller for use with a motor having a shaft, the combination of: a shell having a conoidal dome and a cylindrical wall, impeller blades fixed on said cylindrical wall, a cup fixed within the shell and having a cylindrical portion received within said wall in snug fit relationship therewith to stiifen the same, the cup having a radial flange element cooperating with the conoidal dome to dene an enclosure, a hub projecting into the enclosure, a blade centrifugal blower element fixed on the flange within the cup to stifen the same, the blower acting to induce a iiow of air through the motor for cooling, means securing both of the elements to the hub, and detachable means for connecting the hub to the motor shaft.

4. In a fan construction, the combination of: a motor having a shaft, a shell having a rounded dome and a cylindrical wall, the cylindrical wall encircling a portion of the motor to define an annulus, impeller blades xed on said cylindrical wall, a cup fixed within the shell and having a cylindrical portion received within and contacting said wall, the cup having a radial flange element cooperating with the rounded dome to define an enclosure, a hub Within the enclosure, a bladed centrifugal blower element xed on the flange within the cup for inducing a flow of air inwardly through the motor and outwardly through said annulus for cooling the motor, means securing at least one of the elements to the hub, and detachable means for connecting the hub to the motor shaft.

. OSCAR C. PALMER. EDWARD E. MIX.

REFERENCES CITED The following references are of record in the ile of this patent:

UNITED STATES PATENTS Number Name Date 2,022,417 Gilbert Nov. 26, 1935 2,212,555 Stevens Aug. 27, 1940 2,255,908 Anderson Sept. 16, 1941 2,522,675 Hoover Sept. 19, 1950 

